Electrical socket

ABSTRACT

Electrical socket device includes a socket housing containing a center contact assembly having a resiliently mounted freely movable center contact to enable a lamp mounted in the socket to be correctly positioned in axial alignment in the socket while providing good electrical contact. Spaced ledges are provided in the socket housing on opposite sides of the center contact assembly for engaging the lamp base to maintain proper alignment of the lamp.

United States Patent 1 Orr et a1.

[ ELECTRICAL SOCKET [75] Inventors: Wallace H. Orr; James L. Grindle,

both of Hendersonville, NC

[73] Assignee: General Electric Company, New

York, NY.

[22] Filed: Nov. 1, 1973 [21] Appl. No.: 411,672

[52] US. Cl 339/64 R; 339/180; 339/255 R [51] Int. Cl H011 17/20 Field of Search... 339/48, 49 B, 64, 55, 6773, 339/93, 176 L,180,181,188,199, 253-255, 217 S, 256 SP, 258 S [56] References Cited UNITED STATES PATENTS 1,774,517 9/1930 LeFever 339/180 2,651,763 9/1953 Grimsley 339/93 L 2,721,985 10/1955 Gilbert 339/180 2,890,435 6/1959 Heath 339/255 R 2,921,146 1/1960 Ericson 339/22 T UX 3,170,750 2/1965 Appleton 339/180 3,187,296 6/1965 Brackett 339/217 S 1 June 17, 1975 3,241,136 3/1966 Harrington et al. 339/255 X 3,360,768 12/1967 Winter 339/199 R FOREIGN PATENTS OR APPLICATIONS 1,037,708 9/1953 France 339/180 1,407,061 6/1965 France 339/217 S 1,561,555 2/1969 France 339/l88 R 691,510 7/1965 Italy 339/199 R 815,478 6/1959 United Kingdom 339/255 R Primary Examiner Marion Parsons, Jr. Assistant Examiner-Lawrence J. Staab Attorney, Agent, or FirmS. Greenberg 5 7 ABSTRACT Electrical socket device includes a socket housing containing a center contact assembly having a resiliently mounted freely movable center contact to enable a lamp mounted in the socket to be correctly positioned in axial alignment in the socket while providing good electrical contact. Spaced ledges are provided in the socket housing on opposite sides of the center contact assembly for engaging the lamp base to maintain proper alignment of the lamp.

9 Claims, 3 Drawing Figures ELECTRICAL SOCKET The present invention relates to electrical sockets, and more particularly concerns electrical sockets for removably mounting lamps.

It is an object of the invention to provide an improved electrical socket which is simple in construction, is readily and economically manufactured and provides for good electrical contact with the lamp or other device held in the socket.

It is a particular object of the invention to provide an electrical socket of the above type which has an improved center contact assembly.

Still another object of the invention is to provide an electrical socket of the above type wherein a lamp mounted in the socket is properly positioned and aligned while having good electrical contact with the conductive socket parts.

Other objects and advantages will become apparent from the following description and the appended claims.

With the above objects in view, the present invention in one of its aspects relates to an electrical socket comprising, in combination, a socket housing having an open end and a transverse base portion near its other end and having a central axis, the housing base portion having a pair of spaced slots extending therethrough on opposite sides of the central axis, resilient means arranged on the housing base portion between the slots, and U-shaped conductive contact means having a pair of legs respectively extending loosely through the slots and having a web portion engaging the resilient means, and securing means movably holding the contact means on the housing base portion with the web portion pressed in resilient engagement against the resilient means.

The invention will be better understood from the following description taken in conjunction with the accompanying drawing, in which:

FIG. 1 is an exploded perspective view of an embodiment of the socket device of the invention, with parts broken away;

FIG. 2 is a cross-sectional view in elevation of the socket device showing the base portion of a lamp in assembly therewith; and

FIG. 3 is a top plan view of the socket housing of the FIG. 1 device.

Referring now to the drawing, and particularly to FIG. 1, there is shown an embodiment of the invention which comprises a cylindrical socket housing 1 of electrical insulating material such as porcelain which is open at its top end and is formed with a transverse base portion 2 near its bottom end. In its central region, base portion 2 is formed with a recessed, somewhat circular seat 3 for receiving coil spring 6. On opposite sides of recess 3, base portion 2 has a pair of slots 4, 4' (see FIG. 2) for respectively receiving legs 5a, 5b of a U- shaped conductive contact member 5 which has a web portion 5c which overlies the top of coil spring 6 in the assembled condition of the parts. Legs 5a, 5b of contact member 5 are provided with punched-out projections or barbs 5d, so that when contact member 5 is inserted into slots 4, 4 straddling coil spring 6, barbs 5d engage the underside of base portion 2 for holding contact member 5 in assembly in socket housing 1 with web portion 5c pressing resiliently against and compressing coil spring 6, as seen in FIG. 2.

Legs 5a, 5b of contact member 5 have elongated terminal portions or tabs 5e, 5f, respectively, at their ends which project below the bottom of slots 4, 4' for receiving push-on terminal connectors of known type (not shown).

Fitting within socket housing 1 is conductive screw shell 7 which, in the illustrated embodiment, comprises two curved shell parts 7a, 7!; having tongue and slot portions at their respective adjoining edges for securing the two parts together. It will be understood, however, that screw shell 7 may be of conventional unitary form if desired. Projecting downwardly from opposite sides of the cylindrical threaded portion of screw shell 7 are terminal strips 7a, 7b formed with transverse projections 70, 7d, the arrangement being such that when terminal strips 7a, 7b are inserted through corresponding slots 8, 8a in base portion 2, the ends of the terminalstrips may be twisted slightly so that projections 70, 7d engage the underside of base portion 2 to hold conductive shell 7 in assembly in socket housing 1.

As seen in FIG. 2, the bottom of base portion 2 is formed with integral partitions 2a, 2b serving as insulating barriers between shell terminals 7a, 7b and central contact terminals 5e, 5f.

Base portion 2 is also formed (see FIGS. 1 and 3) with a pair of apertures 10, 10a for receiving screws to secure socket housing 1 with its assembled parts to a fixture or other support (not shown).

On its upper surface, base portion 2 is formed with parallel ledges 11, 12 located inwardly of slots 8, 8a and having substantially co-planar top surfaces. As seen in FIG. 2, showing a lamp 13 of conventional type mounted in socket housing 1 with its threaded base 14 screwed into screw shell 7, ledges ll, 12 are so spaced as to engage the bottom shoulder of lamp base 14 outwardly of contact 15 at the bottom of lamp 13. The ledges thereby serve as stop means for automatically aligning lamp 13 in the proper position along the central axis of socket housing 1 and thus provide consistent location of the light center relative to the optical parts of the lighting fixture such as the reflector. The described arrangement is such that central contact member 5, being resiliently mounted in engagement with coil spring 6, serves in effect as a floating" contact which is readily movable in all directions. Accordingly, when the base of lamp 13 is screwed into contact with the top of contact member 5, the latter member automatically accommodates to the movement of lamp 13 and does not tend to tilt or cock the lamp at an angle to the socket axis as may occur with socket devices of known type, which can result in hindrance to the turning of the threaded lamp base in the screw shell, as well as misalignment of the lamp in its operating position. In the described device, the floating center contact member 5 permits lamp 13 to be readily screwed into the socket until its base comes into contact with positioning ledges 11, 12 so that alignment with the mating contact surface on the lamp base to provide good electrical contact is automatically achieved. Since in the described structure only a single part contains the surface which contacts the lamp base and also the terminal tabs which connect directly to the lead terminals with no intermediate parts or hardware, a low resistance connection is thereby provided. This permits the use of a higher electrical resistance, lower cost contact material such as stainless steel, which has greater strength and higher temperature capability than materials conventionally used for this purpose.

Preferably the top surface of central contact member has an indentation 5g for receiving a complementary projection at the bottom of lamp contact 15, such as is usually present in conventional lamps. Indentation 5g serves not only to provide improved electrical contact between the mating parts but also, by extending into the end of coil spring 6, aids in centering the latter in the assembly.

As will be seen in FIG. 2, legs 5a, 5b of contact member 5 are preferably somewhat spread apart so that their bottom ends are further apart than slots 4, 4, thus maintaining projections 5d in position outwardly of slots 4, 4 to ensure their holding contact member in proper assembly on housing base portion 2.

While the present invention has been described with reference to particular embodiments thereof, it will be understood that numerous modifications may be made by those skilled in the art without actually departing from the scope of the invention. Therefore, the appended claims are intended to cover all such equivalent variations as come within the true spirit and scope of the invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. An electrical socket comprising, in combination, a socket housing having an open end and a transverse base portion near its other end and having a central axis, said housing base portion having a pair of spaced slots extending therethrough on opposite sides of said central axis, resilient means arranged on said housing base portion between said slots, and U-shaped conductive contact means having a pair oflegs respectively extending loosely through said slots and having a web portion engaging said resilient means, said legs having electrical terminal means for making an electrical connection to said contact means, and securing means movably holding said contact means on said housing base portion with said web portion pressed in yieldable engagement against said resilient means, said contact means being freely movable in all directions to accommodate the position of an electrical device adapted to be received in said socket housing in engagement with said contact means.

2. A socket as defined in claim 1, said securing means comprising projections on said pair of legs engaging the underside of said housing base portion. I

3. A socket as defined in claim 1, said resilient means comprising a coil spring compressed between said U- shaped conductive contact means and said housing base portion.

4. A socket as defined in claim 1, and stop means on said housing base portion for engaging the bottom of a lamp adapted to be inserted into said socket housing.

5. A socket as defined in claim 4, said stop means comprising spaced ledges formed in the upper surface of said housing base portion, said ledges having substantially co-planar upper surfaces.

6. A socket as defined in claim 1, and conductive shell means arranged in said socket housing having elongated terminal means extending through said housing base portion.

7. A socket as defined in claim 6, said shell means comprising a composite two-part cylindrical screw shell.

8. A socket as defined in claim 1, said terminal means extending beyond the bottom of said slots.

9. A socket as defined in claim 2, said legs of said contact means diverging from one another, said projections thereon extending upwardly and outwardly there- 

1. An electrical socket comprising, in combination, a socket housing having an open end and a transverse base portion near its other end and having a central axis, said housing base portion having a pair of spaced slots extending therethrough on opposite sides of said central axis, resilient means arranged on said housing base portion between said slots, and U-shaped conductive contact means having a pair of legs respectively extending loosely through said slots and having a web portion engaging said resilient means, said legs having electrical terminal means for making an electrical connection to said contact means, and securing means movably holding said contact means on said housing base portion with said web portion pressed in yieldable engagement against said resilient means, said contact means being freely movable in all directions to accommodate the position of an electrical device adapted to be received in said socket housing in engagement with said contact means.
 2. A socket as defined in claim 1, said securing means comprising projections on said pair of legs engaging the underside of said housing base portion.
 3. A socket as defined in claim 1, said resilient means comprising a coil spring compressed between said U-shaped conductive contact means and said housing base portion.
 4. A socket as defined in claim 1, and stop means on said housing base portion for engaging the bottom of a lamp adapted to be inserted into said socket housing.
 5. A socket as defined in claim 4, said stop means comprising spaced ledges formed in the upper surface of said housing base portion, said ledges having substantially co-planar upper surfaces.
 6. A socket as defined in claim 1, and conductive shell means arranged in said socket housing having elongated terminal means extending through said housing base portion.
 7. A socket as defined in claim 6, said shell means comprising a composite two-part cylindrical screw shell.
 8. A socket as defined in claim 1, said terminal means extending beyond the bottom of said slots.
 9. A socket as defined in claim 2, said legs of said contact means diverging from one another, said projections thereon extending upwardly and outwardly therefrom. 